In PLOS Genetics, researchers from Spain and Germany document interactions that appear to contribute to heterogeneity within mature B cell lymphoma tumors. Using mouse gain-of-function and loss-of-function models, knock-in assays, and mouse lymphoma exome sequencing, the team explored interactions between uracil-N-glycosylase and activation induced deaminase enzymes that influence germinal center B cell mutation and remodeling events behind the hematological malignancy. "Whole exome sequencing revealed that AID heavily contributes to lymphoma [somatic hypermutation], promoting sub-clonal variability and a wider range of oncogenic variants," they write, adding that "our data provide direct evidence that UNG is a brake to AID-induced intra-tumoral heterogeneity and evolution of B cell lymphoma."
An Indonesian team takes a look at the Escherichia coli culprits behind bloodstream infections for a paper in PLOS One. With the help of whole-genome sequencing, the researchers teased out multi-locus sequence types, virulence gene features, and antimicrobial resistance features for 22 E. coli isolates from patients treated for bloodstream infections at a hospital in Jakarta, uncovering a dozen different sequence types, diverse E. coli serotypes, enhanced antimicrobial resistance levels, and clues to the most common phylogroups causing bloodstream infections. The authors also highlight virulence- and toxin-related genes that appear to mark bloodstream infection isolates falling in ExPEC and EAEC groups. They suggest that "routinely screening all bacterial isolates in health care facilities can improve clinical significance," adding that lab surveillance strategies based on genome sequencing "can be a valuable early warning system for emerging pathogens and resistance mechanisms."
Indonesia is home to a recently emerged Chikungynya virus (CHIKV) lineage, according to a paper appearing in PLOS Neglected Tropical Diseases. There, investigators in the UK, Indonesia, and the US share findings from an epidemiological study of CHIKV, focused on parts of the country where relatively little epidemiological data has been collected. The team found that rates of CHIKV infection and seroprevalence were low after samples from nearly 500 patients treated for acute fever at hospitals in Maluku, Kalimantan, and Batam Island from 2017 to 2019, and detected one positive case by RT-PCR. Even so, the authors' subsequent phylogenetic analysis, which included genome sequences for 25 CHIKV isolates from documented Indonesian outbreaks, pointed to the presence of a new CHIKV lineage. They suggest "additional CHIKV surveillance studies in Indonesia and Southeast Asia are needed in order to gain a clearer understanding of transmission routes and hot spots throughout the region."